Tagged: rtl2832

Radio For Everyone New Posts: Building an ADS-B Station, Easy Homemade Beginner ADS-B Antennas

Akos the author of the radioforeveryone.com blog has recently added two new articles to his blog. The first post is a comprehensive guide to setting up your own ADS-B station. The guide focuses on creating a system that is easy to use, has good performance and is value for money. In the post he shows what type of computing hardware is required, what software can be used and what RTL-SDR dongles work best. He also shows what choices are available when it comes to amplification and filtering to improve signal reception and goes on to talk a bit about adapters and the antennas that work best for him.

BuildingADS-Bstation
Building a ADS-B station

 In the second post Akos shows more on how to build your own beginners antennas for ADS-B reception. The post focuses on showing how to modify the stock magnetic mount antenna that comes with most RTL-SDR dongles, and how to build a half-wave ‘spider’ antenna entirely out of coax cable. The post is full of easy to follow images which make it great for beginners.

A home made coax half-wave 'spider' antenna for ADS-B reception.
A home made coax half-wave ‘spider’ antenna for ADS-B reception.

Hacking a Danfoss Wireless Thermostat with an RTL-SDR

Over on his blog Andy writes how he wanted a smart way to control his central heating system with a Raspberry Pi and Arduino microcontroller. He discovered that if he could reverse engineer his existing wireless thermostat then he would have an easy way to control the boiler in his house and with that a smart controller could be made. By reverse engineering the thermostat he also avoids the need to rig up his own control system.

The existing thermostat wireless receiver is a Danfoss RX2. In order to reverse engineer the protocol Andy opened up an older that one he had and saw that it used an Infineon TDA5210 RF receiver chip. Armed with this part number he was able to look up the datasheet and determine the operating frequency. Then by using an RTL-SDR he captured some packets while pressing buttons on the thermostat transmitter and piped the audio file into audacity, where he was able to clearly see the digital waveform.

Andy then wrote a Python program using the ‘wave’ library, which allowed him to easily read binary values for a .wav file. With his code he was able to extract the data from the signal and determine the preamble, sync word, thermostat ID and the instruction code (on/off/learn).

In a future post Andy hopes to show us how he’ll use an RF69 module with an Arduino to actually control the thermostat using the reverse engineered packet knowledge.

Danfoss Wireless Thermostat and a Received Binary Waveform in Audacity
Danfoss Wireless Thermostat and a Received Binary Waveform in Audacity

Radio For Everyone New Posts: Line of Sight, Why USB Cable Quality Matters, Uputronics 1090 MHz Filtered Preamp Review

Over on his radioforeveryone.com blog, author Akos has uploaded three new posts. The first post briefly explains visually what is meant by line of sight when it comes to radio signals. Essentially at UHF and higher frequencies the radio antenna needs to be able to ‘see’ the transmitter, meaning that any blockages such as trees, houses etc will block the signal.

In his second post Akos briefly explains why USB cable quality can matter when it comes to SDRs. He shows that some USB cables tend to pick up more interference than others. 

Finally in his third post Akos reviews the Uputronics 1090 MHz Filtered Preamp. Uputronics is a UK based company that sells various filtered LNA’s. Akos writes how he’s very impressed with the premium packaging, look and feel of the device and thickness of the metal case. In performance tests the preamp together with a V3 dongle with bias tee power clearly improves ADS-B position reports significantly. We note that we also have 1090 MHz filtered preamp from Uputronics (an older model), and can also highly recommend their products.

The Uputronics 1090 MHz Filtered Preamp reviewed on radioforeveryone.
The Uputronics 1090 MHz Filtered Preamp reviewed on radioforeveryone.com

Lowering the Noise Floor on HF with High Quality Coax

Bonito is a company that sells various products such as their own small active antennas. Some examples are the Bono-Whip (20kHz – 300 MHz), GigaActiv (9kHz – 3 GHz) and the MegaLoop (9kHz – 200 MHz). 

Over on their blog they’ve uploaded a post titled “why even good antennas need good coax cable”. The post explains why high quality heavy shielded coax cable may be required to receive HF signals in noisy environments. The author writes how even placing an antenna in a quiet area outdoors may not work if the coax is still run through an high interference environment, such as through a house.

Typically RG58 cable is most commonly used with HF antennas. However, the author noticed that when using RG58 he was still receiving FM stations, even though the antenna that he was using was a MegaLoop with a built in broadcast FM filter. After switching his RG58 cable to H155 coax, the FM station disappeared. H155 coax is low loss and designed for GHz level frequencies, so it has much better shielding from its tighter braid.

The images below also show the difference in noise floor the author saw after replacing all his RG58 with H155 coax. 

http://ReceptionwithRG58Coax

Reception with RG58 Coax

http://ReceptionwithH155Coax

Reception with H155 Coax

Radio For Everyone New Posts: Building an ADS-B Station, Easy Homemade Beginner ADS-B Antennas

Akos the author of the radioforeveryone.com blog has recently added two new articles to his blog. The first post is a comprehensive guide to setting up your own ADS-B station. The guide focuses on creating a system that is easy to use, has good performance and is value for money. In the post he shows what type of computing hardware is required, what software can be used and what RTL-SDR dongles work best. He also shows what choices are available when it comes to amplification and filtering to improve signal reception and goes on to talk a bit about adapters and the antennas that work best for him.

BuildingADS-Bstation
Building a ADS-B station

 In the second post Akos shows more on how to build your own beginners antennas for ADS-B reception. The post focuses on showing how to modify the stock magnetic mount antenna that comes with most RTL-SDR dongles, and how to build a half-wave ‘spider’ antenna entirely out of coax cable. The post is full of easy to follow images which make it great for beginners.

A home made coax half-wave 'spider' antenna for ADS-B reception.
A home made coax half-wave ‘spider’ antenna for ADS-B reception.

Hacking a Danfoss Wireless Thermostat with an RTL-SDR

Over on his blog Andy writes how he wanted a smart way to control his central heating system with a Raspberry Pi and Arduino microcontroller. He discovered that if he could reverse engineer his existing wireless thermostat then he would have an easy way to control the boiler in his house and with that a smart controller could be made. By reverse engineering the thermostat he also avoids the need to rig up his own control system.

The existing thermostat wireless receiver is a Danfoss RX2. In order to reverse engineer the protocol Andy opened up an older that one he had and saw that it used an Infineon TDA5210 RF receiver chip. Armed with this part number he was able to look up the datasheet and determine the operating frequency. Then by using an RTL-SDR he captured some packets while pressing buttons on the thermostat transmitter and piped the audio file into audacity, where he was able to clearly see the digital waveform.

Andy then wrote a Python program using the ‘wave’ library, which allowed him to easily read binary values for a .wav file. With his code he was able to extract the data from the signal and determine the preamble, sync word, thermostat ID and the instruction code (on/off/learn).

In a future post Andy hopes to show us how he’ll use an RF69 module with an Arduino to actually control the thermostat using the reverse engineered packet knowledge.

Danfoss Wireless Thermostat and a Received Binary Waveform in Audacity
Danfoss Wireless Thermostat and a Received Binary Waveform in Audacity

Radio For Everyone New Posts: Line of Sight, Why USB Cable Quality Matters, Uputronics 1090 MHz Filtered Preamp Review

Over on his radioforeveryone.com blog, author Akos has uploaded three new posts. The first post briefly explains visually what is meant by line of sight when it comes to radio signals. Essentially at UHF and higher frequencies the radio antenna needs to be able to ‘see’ the transmitter, meaning that any blockages such as trees, houses etc will block the signal.

In his second post Akos briefly explains why USB cable quality can matter when it comes to SDRs. He shows that some USB cables tend to pick up more interference than others. 

Finally in his third post Akos reviews the Uputronics 1090 MHz Filtered Preamp. Uputronics is a UK based company that sells various filtered LNA’s. Akos writes how he’s very impressed with the premium packaging, look and feel of the device and thickness of the metal case. In performance tests the preamp together with a V3 dongle with bias tee power clearly improves ADS-B position reports significantly. We note that we also have 1090 MHz filtered preamp from Uputronics (an older model), and can also highly recommend their products.

The Uputronics 1090 MHz Filtered Preamp reviewed on radioforeveryone.
The Uputronics 1090 MHz Filtered Preamp reviewed on radioforeveryone.com

Lowering the Noise Floor on HF with High Quality Coax

Bonito is a company that sells various products such as their own small active antennas. Some examples are the Bono-Whip (20kHz – 300 MHz), GigaActiv (9kHz – 3 GHz) and the MegaLoop (9kHz – 200 MHz). 

Over on their blog they’ve uploaded a post titled “why even good antennas need good coax cable”. The post explains why high quality heavy shielded coax cable may be required to receive HF signals in noisy environments. The author writes how even placing an antenna in a quiet area outdoors may not work if the coax is still run through an high interference environment, such as through a house.

Typically RG58 cable is most commonly used with HF antennas. However, the author noticed that when using RG58 he was still receiving FM stations, even though the antenna that he was using was a MegaLoop with a built in broadcast FM filter. After switching his RG58 cable to H155 coax, the FM station disappeared. H155 coax is low loss and designed for GHz level frequencies, so it has much better shielding from its tighter braid.

The images below also show the difference in noise floor the author saw after replacing all his RG58 with H155 coax. 

http://ReceptionwithRG58Coax

Reception with RG58 Coax

http://ReceptionwithH155Coax

Reception with H155 Coax

Receiving GOES Weather Satellite Images with a Small Grid Antenna and an Airspy Mini

GOES is an L-band geosynchronous weather satellite service that can be received typically with a satellite dish. It produces very nice full disk images of the earth. In the past we’ve posted about Lucas Teske’s work in building a GOES receiving system from scratch (including the software decoder for Airspy and RTL-SDR receivers), devnullings post about receiving GOES and also this talk by @usa_satcom on decoding GOES and similar satellites.

Over on Twitter @usa_satcom has been tweeting about his experiments where he has been successfully receiving GOES L-Band weather satellite images with a small grid antenna and an Airspy Mini. In a Tweet he writes that the antenna is an $85 USD Hyperlink 1.9 GHz 22 dBi Grid Antenna made by L-com. A grid antenna may be more suitable for outdoor mounting for many people as they are typically lighter, smaller and more suitable for windy and snowy conditions. As the GOES satellite is in geosynchronous orbit, no tracking motor or tracking mount is required.

Testing a Prototype of the SDRx: A Custom Outernet L-Band RTL-SDR

Recently the Outernet team sent us a prototype of their L-Band tuned RTL-SDR which is called the SDRx for testing. This is an RTL-SDR with RTL2832U and R820T2 chips together with an L-band LNA and filter on the same PCB. It is designed for their Outernet system which transmits from geostationary L-Band satellites. 

Outernet is an L-band satellite service that hopes to be a library in the sky. Currently it is broadcasting down about 20 MB of data a day, with data like weather updates, books, pictures, wikipedia pages, APRS repeats and more.

For their DIY Outernet kit they have been using E4000 or our RTL-SDR V3 dongles, so we speculate that this SDRx is going to be used in the “Lantern” which will be their fully assembled Outernet receiver product. The Lantern looks like it will be a single unit, with patch antenna, battery pack, solar panel, RTL-SDR radio and CHIP built into a plastic enclosure.

The upcoming RTL-SDR base Lantern Outernet Receiver.
The upcoming RTL-SDR base Lantern Outernet Receiver.

The SDRx connects to the computer via a micro USB port. It also has a USB repeater and two USB expansion ports on board. This is useful as Outernet is designed to be used with the CHIP portable computer which only has one USB port. The expansion USB ports can be used for plugging in a portable hard drive which can be used as the storage for downloaded Outernet files.

We’ve been running a version of the SDRx prototype on an Outernet receiver for a number of weeks without issue. The SNR on Outernet signals is about identical to the V3 dongles combined with the external Outernet LNA and no L-band heat problems are observed.

The SDRx Prototype
The SDRx Prototype
Under the shield. SAW Filter, R820T2. LNA top left.
Under the shield. SAW Filter, R820T2. LNA top left.

Ships: New RTL-SDR Compatible Android App for AIS Reception and Plotting

Today an Android app programmer sent a message to let us know about his new open source RTL-SDR compatible AIS app called Ships.  This is a free app that allows you to decode AIS signals, and plot them directly onto an OpenStreetMap/OpenSeaMap or output the data via UDP to another mapping program.

Ships also has another interesting feature which is that it will automatically determine the PPM offset of a dongle, meaning that generic dongles without TCXO’s can be easily used for AIS. It appears to do this by using the AIS signals themselves, so you will need sufficient AIS traffic in your area for the calibration to work.

AIS stands for Automatic Identification System, and is a system used to track the locations of marine vessels. It is similar to ADS-B in that nearby ships can be plotted and tracked on a map by using an RTL-SDR as the receiver. We have a tutorial for PC available here.

The app can be downloaded for free on Google Play, and the open source code is available on GitHub.

Ships RTL-SDR Android App Screenshot
Ships RTL-SDR Android App Screenshot

Cloud-SDR Releases New Client and Server Software for the RTL-SDR

Cloud-SDR is a company that aims to make using SDR over the cloud/network/internet easier. It allows you to set up a remote SDR server that you can access from anywhere. Previously Cloud-SDR was still in development, but now we recently received mail from Cloud-SDR programmer Sylvain that the client and server software has just been released for the RTL-SDR. It appears that it also currently supports the Airspy, BladeRF, SDRplay and PerseusSDR.

The email reads:

I am pleased to inform you that we have just released two softwares compatible with your devices :

  • The Cloud-SDR free client, a windows + Linux (to be released soon) client able to run locally RTL-SDR devices (check the news/turorials, we have featured several times dongles from your blog)
  • The Cloud-SDR streaming server (codenamed SDRNode) , a windows + Linux (to be released soon) multi-user configurable streaming server.

SDRNode is a commercial software but an evaluation version is already available. Both softwares can be downloaded from our store after registration.

Source code for the drivers are already released as open source software through our GitHub repo: https://github.com/cloud-sdr

You can find more details here :

The Cloud-SDR Network
The Cloud-SDR Network

To download the software you must register an account with them at https://store.cloud-sdr.com/my-account. The client is free but the server costs 110 euros for personal and hobby usage, although a 30 day trial version is available. Currently only the Windows Client and Server are available, but they write that Linux should be available soon.

We tested the software out with an RTL-SDR V3. The client installation process was a simple wizard and after installation we launched the Cloud-SDR client by opening the shortcut “cSDRc” in the Start Menu. We found that the hardware needed to be plugged in first for the client to recognize it. The client is basic, but can already demodulate USB/LSB/CW/AM/FMN without trouble. It also has some interesting features:

  1. Dual channel receiver: RXA and RXB are two totally independent receivers;
  2. Geographic integration: Display on map beacons, ADS-B reported airliners, known HF broadcast stations or any geo-localized information coming from the SDRNode server;
  3. GPS compatibility: plug a GPS receiver to your computer and track your location on the map, record signals with your position for later processing (coverage mapping etc.); display the UTC time;
  4. Digital Terrain Elevation: See the terrain elevation around your position, or in the direction of the antenna directly on the map (requires to download the free SRTM3 files from NASA, with 90m resolution);
  5. MP3 audio recording: record to mp3 the demodulated streams to reduce disk requirements;
  6. Chat with other users connected to the SDRNode Group: when used as a remote client for the SDRNode streaming server, you can interact with other users with messages or station spotting;
  7. Time-domain analysis: the MSR mode enables analysis of any sub-band and displays in real time the time domain signals of the selected spectrum portion. This sub-band can also be recorded (with geographic position if GPS is connected) and processed with provided MATLAB®.
The Cloud-SDR Client Software
The Cloud-SDR Client Software

Next we tested the evaluation version of the SDR-Node server software on a remote laptop with an RTL-SDR connected. Again installation was easy, just follow the wizard after ordering the evaluation version. SDR-Node installs itself as a Windows service which starts up automatically on boot. To set up the Node we followed the guide shown in the video below. To connect with the client you need to know the IP address of the remote computer, the port is 8080, and the certificate is displayed on the server PC SDR-Node dashboard. We note that we also had to disable the Windows firewall to get it to connect, but it should be possible to also add SDR-Node to the firewall whitelist.

https://www.youtube.com/watch?v=waRP7PIcOBc

When streaming it appears that only 1/4 of the SDR sample rate can only be sent over the network. There are also compression options which can be used on slower networks or the internet to reduce bandwidth. Using the interface while in network mode was slightly laggy, but the waterfall and audio was smooth.

Overall everything worked as expected and it looks to be a very useful tool. More information is available at cloud-sdr.com. Some already existing alternative remote SDR streaming software that supports the RTL-SDR includes rtl_tcp, the SDR Console V2 server, OpenWebRX and ShinySDR.